Exclusion Criteria: Psychiatric Disorders. RA subjects with a current or lifetime history of a major Depressive Disorder or other Diagnostic and Statistical Manual of Mental Disorders IV (DSM-IV) psychiatric disorder (e.g. substance dependence) will be excluded due to the known effects of major depression on pain. Although depressive symptoms can occur in as many as 40% of RA patients, the prevalence of syndromal major depressive disorder is considerably less, and we do not anticipate that exclusion of current or lifetime history of major depressive disorder will substantially alter subject flow. More than 75% of a selected sample of RA subjects at University of California, Los Angeles (UCLA) affiliated clinics does not have a history of co-morbid psychiatric disorder.